The purpose of this Core is to stimulate a collaborative multi-disciplinary program of research on how environmental exposures at particular stages in the life cycle affect susceptibility to disease and to deficits in development. The Core members have unique expertise and wide ranging interests in reproductive and perinatal epidemiology, developmental biology, and teratology. Therefore, during the first funding period, the focus will be on exposures from preconception through childhood. Core investigators have the necessary interests and expertise to, within the context of the Center, implement multi-disciplinary projects that incorporate mechanistic information, epidemiologic designs, and state-of-the-art biomarkers. The aims of the Developmental Susceptibility Core are to: 1) foster and expand collaborative research on the effects of exposures during vulnerable stages in development, including adverse outcomes of pregnancy, birth defects, developmental deficits and childhood cancer; 2) establish effective mechanisms for sharing ideas, discussing research in progress, and fostering new interdisciplinary ventures that integrate laboratory, clinical, and epidemiologic approaches to developmental studies; 3) promote incorporation of molecular and genetic markers into traditional epidemiology studies of reproductive and developmental outcomes; and, 4) provide a resource to the Center for knowledge related to multi-generational studies, developmental biology and teratogenicity of specific exposures of common interest.